Circular buffer datatype

source/engine/circbuf.c

@@ -0,0 +1,52 @@
+#include "circbuf.h"
+
+
+
+
+struct circbuf circbuf_init(size_t size, int len)
+{
+    struct circbuf new;
+    new.size = size;
+    new.len = len;
+    new.data = calloc(size, len);
+    new.head = new.tail = new.data;
+
+    return new;
+}
+
+void cbuf_append(struct circbuf *buf, void *data, int n)
+{
+
+    for (int i = 0; i < n; i++) {
+        memcpy(buf->head, data+(buf->size*i), buf->size);
+
+        buf->head += buf->size;
+
+        if (buf ->head == buf->data + buf->size*buf->len) buf->head = buf->data;
+    }
+
+/*
+    size_t cpbytes = n * buf->size;
+    size_t rembytes = (buf->size * buf->len) - (buf->head - buf->data);
+
+    if (cpbytes <= rembytes)
+        memcpy(buf->head, data, cpbytes);
+    else {
+        memcpy(buf->head, data, rembytes);
+        cpbytes -= rembytes;
+        buf->head = buf->data;
+        memcpy(buf->head, data+rembytes, cpbytes);
+    }
+*/
+
+}
+
+void *cbuf_take(struct circbuf *buf)
+{
+    void *ret = buf->tail;
+
+    if (buf->tail == buf->data + buf->len*buf->size) buf->tail = buf->data;
+    else buf->tail += buf->size;
+
+    return ret;
+}